The Dynamics of the S-Web and Implications for the Solar Wind and Heliosphere

[摘要] The Sun;;s powerful magnetic field is responsible for all the observed properties of the highly dynamic corona and heliosphere, from the solar UV--X-ray radiation, to the composition of solar wind plasma, to the location and acceleration of energetic particles throughout the solar system. Two long-standing mysteries posed by the in-situ observations are the large angular extent of slow solar wind about the heliospheric current sheet (HCS) and the large longitudinal spread of impulsive solar energetic particles (SEPs). In the classical picture of the solar/heliospheric magnetic field, slow solar wind should occur only near the HCS and impulsive SEPs should occupy only a narrow spread about the point of origin in the corona. The recently proposed Separatrix-Web (S-Web) Theory postulates that these observations can be explained by the dynamical interaction of open and closed flux in regions of complex magnetic topology. This dissertation presents the first numerical simulations of the dynamic S-Web and rigorously calculates its effects on the slow solar wind and SEP populations. We show that photospheric motions at coronal-hole boundaries are responsible for the release of slow solar wind plasma from the magnetically closed solar corona, specifically through prolific interchange magnetic reconnection. The location of this plasma once it is released into the solar wind depends strongly on the geometry of the coronal-hole flux. We demonstrate how the dynamics at the boundaries of narrow corridors of open flux (coronal-hole corridors) are responsible for the observations of slow solar wind plasma at high latitudes in the heliosphere, far from the HCS. Furthermore, we show how energetic particles that are accelerated within a small region on the Sun near a coronal-hole corridor can be observed many tens of degrees in longitude away from the flare region in heliosphere. At the heart of the S-Web theory is the concept that the detailed topology of the Sun;;s magnetic field is imprinted directly on the heliosphere. Our results show that the complex and dynamic mapping of the magnetic field from the Sun to the heliosphere is essential for understanding the observed properties of interplanetary plasma and particles.

[发布机构] University of Michigan

[效力级别] Solar Magnetic Field

[关键词] Slow Solar Wind;Solar Magnetic Field;Solar Energetic Particles;Sun;Heliosphere;Solar Wind;Atmospheric;Oceanic and Space Sciences;Science;Atmospheric, Oceanic & Space Science